Pregnant women exposed to stress are more likely to deliver a stillborn baby, says a new study.

Stillbirth is when the fetus dies in the uterus after 20 weeks of pregnancy. One in 160 pregnancies end this way, and African-American women have double the chance of it happening.

Prior to this study, stillbirths had been linked to birth defects, problems with the placenta, infections and chronic health conditions.

“[But], medical conditions only account for some of the causes of these poor pregnancy outcomes,” says Marian Willinger, PhD, author of the study and acting chief of the Pregnancy and Perinatology Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

“Some of the conditions, such as hypertension, obesity and autoimmune disorders increase the risk for stillbirth and are more common in African-Americans. However, these appear to account for only a small portion of the disparity,” she says.

Stress not uncommon

A total of 2,430 women were questioned – 614 women with stillbirths and 1,816 with live births. The study found an increased chance of stillbirth with each additional stressful life event the women encountered. The stressful events involved financial, emotional, traumatic or partner-related issues.

“We were surprised at how common stressful life events were in pregnant women’s lives,” Willinger admits.

Almost one in five women with stillbirths and one in 10 women with live births had experienced five or more different stressful life events. Nearly all of the women had experienced at least one.

African-American women reported a higher number of stressful events as compared to the non-black women in the study. This is thought to be a factor in why African-American women are more affected.

Connecting the two

According to Willinger, stress has been shown to increase inflammation during pregnancy which may trigger early birth. Stress is also related to a higher risk of infection which is associated with stillbirths. But, she adds, more research is needed to find the exact link between the two.

Dr. Renee Volny, an obstetrician-gynecologist in Georgia, is skeptical.

“There is no known mechanism by which stress alone causes stillbirths,” Volny says. “For example, having an argument with someone while pregnant is not a known cause of stillbirth.”

However, she says, a different connection may be possible.

“Stress is often a symptom of less than optimal situations that affect livelihood and health,” Volny says. “A healthy and happy mother increases the chances of having a healthy baby.”

The women with live births were more likely to be between 20 and 39 years of age with private insurance, of normal weight, not diabetic and married. This falls in line with the national CDC statistics which show that nearly 71 percent of black births were outside of marriage compared to only 27 percent of white births.

More on the horizon

Willinger hopes that the next steps involve identifying women who are particularly vulnerable to these stressful life events and providing additional support in order to improve the outcome of their pregnancies.

Volny is also optimistic.

“Hopefully, with full implementation of health reform in 2014, we will start to see a decrease in stillbirths among black women,” says Volny, who is interim associate director of health policy at the Satcher Health Leadership Institute at the Morehouse School of Medicine, and a contributing writer at Policy Prescriptions, LLC.

“But, medicine alone does not hold the answer to reducing stillbirths. Much of what affects pregnancy happens outside of the doctor‘s exam room. This study demonstrates that.”

Dr. Tyeese Gaines is a physician-journalist with over 10 years of print and broadcast experience, now serving as health editor for theGrio.com. Dr. Ty is also a practicing emergency medicine physician in New Jersey. Follow her on twitter at @doctorty or on Facebook.